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[英]How to apply a JavaScript function to different elements by assigning the function to different buttons
[英]Assigning a function to an array of javascript buttons
當我單擊這些按鈕時,我希望將sessionStorage中的項目分配為true,這表示按下了按鈕。 單擊第四個按鈕時,它是用來顯示選擇了哪些信息以了解更多信息。
現在我的按鈕什么也沒返回,我想不通如何遍歷這個過程並為每個按鈕分配一個功能
//simple html to print four buttons.
<!DOCTYPE html>
<html>
<head>
<title>Green Things</title>
<script type="text/javascript" src="example.js"></script>
</head>
<body>
<div><button id="moreAboutGrass" type="button" class="button">Send me more information about Grass</button></div>
<div><button id="moreAboutMolluscs" type="button" class="button">Send me more information about Green Molluscs</button></div>
<div><button id="moreAboutSweaters" type="button" class="button">Send me more information about Green Sweaters</button></div>
<div> <button id="infoChosen" type="button" class="button">Things you want more information about </button></div>
<div><output id = "output"></output></div>
</body>
</html>
window.onload = function() {
//getting an array of all the buttons
var y = document.getElementsByClassName("button");
//looping through all the buttons
for(count = 0; count < y.length; count++){
//Assigning an operation to the button
document.getElementById(y[count].id).onclick = function(count) {
//Assigning a variable to be the id name of button passed into this function
z = y[arguments[i]].id;
//If the button is the fourth button
if ( z == "infoChosen" ){
//Add in the things which were selected
document.getElementById("output").innerHTML = "";
if (sessionStorage["moreAboutMolluscs"] == "true"){
document.getElementById("output").innerHTML += "Green Molluscs\n";
}
if (sessionStorage["moreAboutSweaters"] == "true"){
document.getElementById("output").innerHTML += "Green Sweaters\n";
}
if (sessionStorage["moreAboutGrass"] == "true"){
document.getElementById("output").innerHTML += "Grass\n";
}
}else{
//if the button was on of the first 3 just set a variable to true so it can be printed later
sessionStorage.setItem(z, "true");
}
}
}
如果單擊第一個按鈕,然后單擊第四個按鈕,則輸出應為
Green Molluscs
如果單擊第一個和第三個按鈕,然后單擊第四個按鈕,則輸出為
Green Molluscs Green Sweaters
我需要循環執行
嘗試這個
<!DOCTYPE html> <html> <head> <title>Green Things</title> <script type="text/javascript"> window.onload = function() { //getting an array of all the buttons var y = document.getElementsByClassName("button"); //looping through all the buttons for(count = 0; count < y.length; count++){ //Assigning an operation to the button var aa = y[count].id; document.getElementById(y[count].id).onclick = function(aa) { var z = aa.currentTarget["id"]; if ( z == "infoChosen" ){ document.getElementById("output").innerHTML = ""; if (sessionStorage["moreAboutMolluscs"] == "true"){ document.getElementById("output").innerHTML += "Green Molluscs\\n"; } if (sessionStorage["moreAboutSweaters"] == "true"){ document.getElementById("output").innerHTML += "Green Sweaters\\n"; } if (sessionStorage["moreAboutGrass"] == "true"){ document.getElementById("output").innerHTML += "Grass\\n"; } }else{ //if the button was on of the first 3 just set a variable to true so it can be printed later sessionStorage.setItem(z, "true"); } } } } </script> </head> <body> <div><button id="moreAboutGrass" type="button" class="button">Send me more information about Grass</button></div> <div><button id="moreAboutMolluscs" type="button" class="button">Send me more information about Green Molluscs</button></div> <div><button id="moreAboutSweaters" type="button" class="button">Send me more information about Green Sweaters</button></div> <div> <button id="infoChosen" type="button" class="button">Things you want more information about </button></div> <div><output id = "output"></output></div> </body> </html>
在這種情況下,我會做不同的事情。 在我看來,最好的選擇是為每個按鈕創建一個函數,例如<button onclick="myFunction()">Click me</button>
然后該函數會將變量更改為true或false。 而且,當您單擊第四個按鈕時,也可能是最好的選擇,對於正確的輸出,每種可能性都應使用switch語句。
我還沒有那么豐富的編碼經驗,所以這可能不是最有效的方法,但是希望對您有所幫助。
好吧,首先,您沒有正確訪問sessionStorage
。 看到這個 。 而且您正在做的事情看起來有點混亂。 我在下面的答案中整理了代碼,因此在這里僅作一些解釋。
我決定使用document.getElementsByTagName("button");
來獲取所有按鈕document.getElementsByTagName("button");
它可能並不總是適用,但是適合您的情況。
我將使用長度的for循環更改為僅使用of
運算符。 它基本上遍歷數組,而無需對其進行長度調整。
我認為有關將內容放入sessionStorage的其他部分很簡單,但是如果您不確定,請問我,我會重寫它。
jsfiddle: https ://jsfiddle.net/ryvcvp42/
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